Abstract
A specific allotrope of titanium dioxide (anatase) was synthesized both with a standard thermodynamic morphology ({101}-anatase) and with a highly anisotropic morphology ({001}-anatase) dominated by the {001} facet (81%). The surface chemistry of both samples after dehydroxylation was studied by 1H NMR and FT-IR. The influence of surface fluorides on the surface chemistry was also studied by 1H NMR, FT-IR and DFT. Full attribution of the IR spectra of anatase with dominant {001} facets could be provided based on experimental data and further confirmed by DFT. Our results showed that chemisorbed H2O molecules are still present on anatase after dehydroxylation at 350 °C, and that the type of surface hydroxyls present on the {001} facet is dependent on the presence of fluorides. They also provided general insight into the nature of the surface species on both fluorinated and fluorine-free anatase. The use of vanadium oxychloride (VOCl3) allowed the determination of the accessibility of the various OH groups spectroscopically observed.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 14362-14373 |
| Number of pages | 12 |
| Journal | Physical Chemistry Chemical Physics |
| Volume | 20 |
| Issue number | 21 |
| DOIs | |
| State | Published - 2018 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: This work was supported by the King Abdullah University of Science and Technology (KAUST). We warmly acknowledge the help of the KAUST Core labs, and the Supercomputing Laboratory at KAUST for the CPU time attributed to this research work. The authors thank Zhen Cao (KCC-KAUST) for the fruitful discussion.